This invention is directed to an apparatus and method for sealing the fin of a gable-top carton. More specifically, the invention pertains to a top sealer jaw assembly for sealing and creasing the gable panels and fin of a gable top carton, and a method therefor.
Gable top cartons are in widespread use. Such cartons have been known for most of the twentieth century. The characteristic simplicity and widespread acceptance have helped to maintain their popularity as cartons for traditional products, such as liquid food products, for example, milk and juice.
Improvements to gable top cartons continue and in one such improvement, access to the product is provided by a spout that is integrally sealed to one of the gable panels. In a “conventional” spout arrangement, an opening is formed in the gable panel and a plastic or like spout is welded or sealed to the panel. A cap, such as a threaded closure is fitted onto the spout to provide resealability of the container. Such spouts have come into widespread use and acceptance for their ease of access to the product and their ability to help maintain product freshness.
In that both the products and consumers' desires vary, as would be expected, gable top cartons are provided in different sizes that correspond to different volumes and package standards. For example, gable top cartons are provided in standard sizes of 70 mm×70 mm, 70 mm×95 mm, 91 mm×91 mm and 95 mm×95 mm.
In order to seal the top fin of these cartons, known form, fill and seal packaging machines use a horizontally reciprocating jaw or anvil arrangement. The anvils include openings to accommodate the package spouts and caps so that the spouts and caps do not get crushed by the moving anvils. The anvils are mounted to the packaging machine by a pair of pivoting arms such that the movement of the anvils is actually a slight arcuate movement with the anvils contacting the carton in a downward movement portion of the cycle. Such an arrangement is illustrated in Cicha, U.S. Pat. No. 6,430,899, which is commonly assigned with the present application and is incorporated herein by reference.
While this arrangement works quite well for its intended purpose, it has been found that the downward movement of the anvils can result in scraping along the top fin and/or plowing down on the carton gable panels, both of which actions are to be avoided. In addition, it is sometimes difficult to accommodate the closure spouts and/or caps used with today's packages. It has been found that the anvils often contact (e.g., scrape) the closures during the top sealing process. Moreover, the anvil arrangements need to be different for each different carton size.
Accordingly, there is a need for a standard top sealer that is usable with a variety of different sizes of cartons. Desirably, such a top sealer employs a motion that reduces or eliminates downward motion on the top fin as the fin is being sealed. More desirably, such an arrangement eliminates the plowing down effect of known sealers and accommodates today's known closure systems.